The study drug, squalamine lactate, inhibits growth of solid tumors by inhibiting the development of a blood supply to the tumor without direct cytotoxicity to tumor cells. It has not been previously tested in human subjects. The purposes of this study are to determine the maximum tolerated dosage, determine the qualitative and quantitative toxicity charcteristics, determine the recommended dose as a continuous five day infusion, and characterize the pharmacokinetic and pharmacodynamic charcteristcs of the drug.